A digital image obtained by an imaging apparatus includes a plurality of pixels. Color and density expressed by the pixels creates the entire image. There can be a pixel called an anomalous pixel among the plurality of pixels.
The anomalous pixel means a defective pixel outputting a signal that departs from a predetermined output range with respect to a predetermined input due to an abnormal condition of a circuit or a device in the imaging apparatus, or a pixel outputting another abnormal signal or a defective value.
Since the anomalous pixel influences the image quality of a captured image, the anomalous image is corrected with a replacement method using an average pixel value of pixels around the anomalous pixel and an image after the correction is provided to a user.
A medical field demands checking the position of an anomalous pixel subjected to correction processing. Because the correction processing changes a pixel value of the anomalous pixel and an image before the correction thus needs to be checked at the position of the anomalous pixel.
With a conventional technology for meeting the demand, a radiographic image is related to the position of the anomalous pixel, and the position of the anomalous pixel is superimposed to the entire radiographic image and is then displayed.
The check of the anomalous pixel includes that of the presence or absence of the anomalous pixels and whether or not a number of the anomalous pixels in a predetermined region exceeds a predetermined threshold. However, only the display operation of the defective pixel cannot realize acquisition of the information.